open water dive
if danny Huston dove at that depth without a pressure dive suit and helmet(like portrayed in rescue scene) he would have been crushed.
shareHe was already acclimated to the high pressure. The dive suit is mostly to provide protection from the elements (cold) along with air and communication.
He killed sixteen Czechoslovakians. Guy was an interior decorator.
This reply from micirisi is 100% accurate.
The OP might be under the common misconception though that the deep water pressure would literally have crushed the diver, which is not the case at all.